| 摘要 |
A power amplifier that utilizes a minimum amount of power, and, simultaneously, inhibits the generation of distortion is described. The power amplifier includes a differential input terminal, an output terminal, a negative feedback circuit, and an adaptive bias current control circuit. The differential input terminal receives a first voltage and a second voltage respectively through a first terminal and a second terminal, and outputs a current corresponding to a difference in the input voltages. The output terminal outputs an amplified signal corresponding to the current output by the differential input terminal. The negative feedback circuit performs negative feedback of an output voltage of the output terminal and provides the output voltage to the first terminal of the differential input terminal. The adaptive bias current control circuit controls a bias current of the output terminal according to distortion information corresponding to the difference between the first voltage and the second voltage. Using the power amplifier, the bias current of the output terminal is increased when crossover distortion is severe, and decreases the bias current of the output terminal when there is no signal and no distortion. Thus, the level of power consumption is reduced and the generation of distortion is prevented.
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